High capacity draft gear with friction and rubber spring cushioning elements



July 1,1958 D. s. CAMPBELL HIGH CAPACITY DRAFT GEAR WITH FRICTION AND RUBBER SPRING GUSHIONING ELEMENTS 5 Sheets-Sheet 1 Filed Oct. 28, 1953 July 1, 1958 s, CAMPBELL 2,841,292

HIGH CAPACITY DRAFT GEAR WITH FRICTION AND RUBBER SPRING CUSHIONING ELEMENTS Filed 001;. 28, 1953 5 Sheets$heet 2 29 w I. I

IN V EN TOR.

July 1, 1958 D. s. CAMPBELL 2,841,292

HIGH CAPACITY DRAFT GEAR WITH FRICTION AND RUBBER SPRING CUSHIONING ELEMENTS 5 Sheets-Sheet 3 Filed 001;. 28, 1953 v INVENTOR. W

' July 1, 1958 D. s. CAMPBELL 2,841,292 HIGH CAPACITY DRAFT GEAR WITH FRICTION AND RUBBER SPRING CUSHIONING ELEMENTS 5 Sheets-Sheet 4 Filed Oct. 28, 1953 if I gim INVENTOR. flare/KW July 1, 1958 D. s. CAMPBELL 2,841,292 HIGH CAPACITY DRAFT GEAR WITH FRICTION AND RUBBER SPRING CUSHIONING ELEMENTS 5 Sheets-Sheet 5 Filed 001;. 28, 1953 AV A HIGH CAPACITY DRAFT GEAR WITH FRICTION AND RUBBER SPRING CUSHIONING ELENIENTS David S. Campbell, Glen Ellyn, Ill., assignor to Cardwell Westinghouse Company, a corporation of Delaware Application October 23, 1953, Serial No. 388,788

Claims. (Cl. 213-32) This invention relates to draft gears for railroad cars, and has for its principal object to provide a gear with extremely high capacity and practically no solid point.

Generally speaking, this is accomplished with a friction cushioning element and a spring cushioning element in tandem acting in series and in which the friction element controls the recoil on release by energy absorption.

Further objects and advantages will be apparent as the description is read in connection with the accompanying drawings, in which:

Fig. 1 is a horizontal section through familiar parts of a freight car showing the draft gear applied;

Fig. 2 is a vertical section of the same;

Fig. 3 is an enlarged horizontal section through the draft gear and portions of the draft rigging showing the gear in full release;

Fig. 4 is a similar view showing the draft gear compressed in buff;

Fig. 5 is a vertical section through the draft gear and the front follower with the draft gear in full release;

Fig. 6 is a similar View with the draft gear compressed;

Fig. 7 is a cross section on the line 7-7 of Fig. 5;

Fig. 8 is a front end view of the draft gear;

Fig. 9 is a perspective view of the draft gear housing;

Fig. 10 is a perspective View of the intercalated plates and friction shoes forming a part of the friction cushioning element;

Fig. 11 is a perspective view of the plunger, also forming a part of that cushioning element;

Fig. 12 is a wedge spring seat forming a same;

Fig. 13 is a horizontal section similar to Fig. 3 showing a modified'form;

Fig. 14 is a vertical section of the draft gear alone; and

Fig. 15 is a perspective view of the plunger of the modified form.

But these drawings and the corresponding description are for the purpose of illustrative disclosure only, and are not intended to impose unnecessary limitations on the claims.

In Figs. 1 and 2, the draft gear, indicated generally by 10, is shown in the familiar surroundings of center sills ll, draft gear lugs 12, draft yoke 13, coupler butt or shank 14, draft key 15, coupler carrier iron 16, draft gear carrier 17, coupler horn is, and striking plate 19 (all corresponding to Fig. 10.51 of Car Builders Cyclopedia, 1946, p. 944). These parts are so familiar that no specific description is deemed necessary.

The draft gear housing, generally indicated at 26 (Figs. 39), includes a rear chamber 21 for a cushioning element, here shown of the rubber spring type, and a front chamber 22 for a friction cushioning element in open communication with the rear chamber and open at the front.

The spring cushioning element, generally indicated by 23, includes rubber spring units 24 and spacers 25 along with a follower 26 at the front.

The friction cushioning element, generally indicated part of the 27, includes a plunger 23 (Figs. 3, 4, and 11) in thrust relation to the follower 26 and having opposite wedge surfaces 29 together with friction shoes 30 having wedge surfaces 31 cooperating with the wedge surfaces 29 on the plunger and wedge surfaces 32 cooperating with a wedge spring seat 33.

The plunger 28 (Figs. 5, 6, and 11) includes two spaced arms 34 extending rearwardly from the wedge surfaces 29 and connected by a base or spring seat 35 which comes against the front face of the follower 26, as appears in Figs. 36.

An inner spring 36 extends through an opening 37 in the base 35 and an opening 38 in the wedge spring seat 33 to a spring seat 39 on the plunger 28, and acts between the follower 26 and the plunger 22:- to urge the latter toward released position.

An outer spring 40 extends between the spring seat 35 and the bevelled spring seat 33, which cooperates with the inclined surfaces 33 on the Wedges 3i and maintains a predetermined constant loading on the friction elements at all times. it also urges the wedges toward released position.

Associated with and acted upon by the friction shoes 39 are a group of intercalated plates 5, 6, '7, 8, and 9, one group at each side of the cushioning element. The plates 6 and 8 are movable with respect to their associates and the casing, and serve as thrust members between the front follower ll and the follower 26 for the rubber spring element.

The plates 5, 7, and are stationary, and are so held within the casing by vertical ribs 42 and 43 (Figs. 3 and 4), horizontal ribs (Figs. 5 and 6), and end flanges 45 (Figs. 5, 6, 8, and 9).

Assembly For convenience in assembly, the housing 26 is provided with openings 7% and 7:. (Fig. 9), and the follower 26 is provided with openings 72 (Figs. 2 and 3).

After the follower 26 and the spring 23 have been inserted one part at a time through the opening '79 and brought approximately into the position shown in Fig. 3, the spring is compressed and assembly pins are inserted in the openings if and 72 to hold it compressed while the friction cushioning element is assembled in the front chamber 22.

The stationary friction plates 5, '7, and 9 are inserted, the plunger 28 and springs 36 and 40 with the spring seat 2, and the shoes 36 are brought into loosely assembled relation and the plates 6 and S slid in place. Then the spring 23 is compressed slightly, the assembly pin is removed, and the spring released.

Alternatively, the rear wall of the housing may be made separate from the body portion, and assembly can then be accomplished without any preliminary compression.

The capacity of the gear can be varied by changing the angle of the Wedge surfaces 29 and 31.

The surfaces 32 and 33 are best on the angle of repose of the metal. They are inclined to promote free movement.

Generally speaking, the ordinary draft gear for freight cars has a capacity on the order of 21,000 foot pounds with a nominal travel of 2 /8", which will handle a ton car at approximately four miles an hour. According to this invention, a draft gear may have a capacity on the order of 40,000 foot pounds in 2 /2" travel; and, by increasing the total travel to 3 /4, the loading on the rubher elements may add capacity on the order of 25,000 pounds in the last 2 1 of travel beyond the stated 2 /2" of travel mentioned.

Operation In buff, the plunger 28, acting on the Wedge shoes 39,

puts pressure on the intercalated plates, creating friction to. t ,2

absorb energy. In the same movement, the plunger through its base 35 acts upon the follower 26 to transmit the travel to the rubber spring element 23 and'add'cushioning resistance and energy absorption.

i That action is 'su'fiicient to take care 7 ordinary buffing shocks, and the parts 'are'so designed of a great many preferably to confine action to that for a short distance- 7 for example, /1. e i

As the travel continues, the front follower 41 picks up,

' first, the movable plates 6, and if there is travel enough then the movable plates 8, each'time adding additional friction while the plunger adds pressure, and the whole addsload to the rubber cushioning element 23, producing shock resistance and energy absorption of high capacity.

Upon release, the coil springs urge the parts of the friction gear toward release and control the'recoil of the rubber spring element, which forces the parts from a compressed position (illustrated in Fig. 4) to the full releaseposition shown in Fig. 3.

[Modification Operation of modification In buff, the plunger 28, acting upon the wedge shoes St), the wedge spring, seat 32, and the large spring 40,

simultaneously puts pressure on the intercalated plates having outwardly facing friction surfaces cooperating with said opposed friction. surfaces, there beingjat least 7 a one friction surface on each wedge, said friction cushioning element being actuated by relative movement betweentsaid front wedge and said housing to translate at least a portion of the longitudinal forces applied to the gear into lateral forces to develop friction at 'SHidfOpposedtfric'tioii surfaces; and resilient"meansi'eacting between the front wedge and said cushioning unit andurgw ing the front wedge longitudinally away fromsaid cushioning unit toward full release position for said'friction cushioning element, whereby upon release of the gear the recoil energy is partially absorbed by said friction cushioning element, after which said last-mentioned resilient means releases said'friction cushioning element.

2. In a draft gear for mounting in the draft pocket of a railway car, said pocket having front and rear stops: a housing having laterally spaced opposed friction surfaces therein; and a cushioning mechanism supported within said housing to' react between saidfr'ontfand rear stops and comprising a cushioning unit of a rubber spring type, and an energy absorbing friction cushioning element mounted in tandem with said cushioning unit for series action therewith and including a front wedge; a rear wedge longitudinally spaced therefrom, laterally spaced wedge shoes positioned between and co acting with said front and rear wedges and having outwardly 'facing friction surfaces cooperating with said opposed and transmits pressure to the follower 26 for the rubber spring element 23. The result is combined friction absorption withless rubberfspring action than before, and

this, is sufiicient for ordinary buffing shocks inv general service. j After a travel of /2" by the plunger 28, the base comesagainst the follow'er 26, the follower 41tcomes against the end of movable plate 6, and the operation proceeds much as described in connection with the first form. e r t A similar modification can be made in the device disclosediiri my applicationSe'rial Number 362,256, filed June '17, 1953.1 V V In orderlto temporarily shorten the gear for inserting it intothe i dr'aftgear' pocket between the lugs 12, the gear is compressed slightlyjfrom the position shown in Figs. '5, and 14. tobring thecpenings 6i) and 61in the housing and thetplungeriinto alignment when shear pins are insert-ediand the pressure released. Thereafter, the

draft gear is an assembled unit for storage, handling, and

installing. r

The first normal shock inbutf .will shear the pins, and

thereafter the gear will assume normal release' position;

as shown in Figs. 3 and 13; i I claim: 7 t t 1.,In a drafttgear for mounting in, the draft pocket Vof a railway car, said pocket having front and rear stops:

'a housing having laterally spaced opposed friction sur-' faces therein; and a cushioning tmech anisrn supported within' said'housing to react between said front and rearstops and comprising a'cushioning unit of the rubber 'spring'typ'e, and anenergy absorbing friction cushioning element mounted in tandem with said cushioning unit for series action therewith and including a front wedge, a rear wedge longitudinally spaced from said front 'Wedge and urged tow ard said front wedge by said cushioning unit, and laterally spaced wedge shoes positioned between and coacting with said front and rear wedges and friction surfaces and resilient means 'reactingfb'etweeh said rear wedge and said cushioning unit, there being at least one friction surface on'each wedge, said friction V cushioning element being actuated byrelative movement between said front wedge and said housing to translate at least a portion of the longitudinal forces applied to the gear into lateral forces to develop friction atfsa'id opposed friction surfaces; and additionalresilient'ineans reacting between the front wedge and 'said cushioning unit and urging the front wedge longitudinally away from said cushioning unit toward' full release position-for said friction cushioning element, whereby upon release of the gear the recoil energy 'is partially absorbed by said friction cushioning element, after which said last-mentioned resilient means releases said friction cushioning element.

3. In a draft gear for mounting in the draft pocket of a railway car, said pocket having front and rearjstops: a housing including a rear chamber and a front chamber in open communication with the rear chamberand'open at the front; a front follower movable longitudinally 'rela-' tive to said housing; a cushioning unit of the jubber spring type in said rear chamber; and an energy absorbing'friction cushioning elern'ent mounted in saidfront chamber in tandem with said cushioningtunitfor series 7 action therewith. and including a front wedge, a rear" 7 'wedge'longitudinally spaced from said front wedge and V V urgedtoward said front wedge by said cushioning unit, 7

laterally spaced wedge shoes'positioned between and coacting with said front and rear wedges and having'ou t wardly facing friction surfaces, there being at least'one friction surface'oneach wedge, and a group of inter-' calated stationary and movable friction plates "disposed in said front chamber at each side thereof and providing in- V wardly facing friction surfaces cooperating with' said outwardly facing friction surfaces; with the' movable plates of said groups projecting"longitudinally out'of the open front of said housing for engagement' with said front follower during a' portion of the relative movement between said front follower and said housing, said'frict tion cushioning element being actuated 'by relative movement between said-front follower and said housing t'o translateat least a portion of the longitudinal forces ap plied to the gear into lateral forces to develop frictionat 'said friction surfaces, and resilient means reacting be- ;tween the front wedge and said cushioning unit and urging the front wedge longitudinally away;f rom;said cushioning unit toward full release position for said friction cushioning element, whereby upon release of the gear the recoil energy is partially absorbed by said friction cushioning element, after which said last-mentioned resilient means releases said friction cushioning element.

4. In a draft gear for railroad cars, a plunger including a wedge body having a bufiing surface on one side and having opposite wedge faces on the side opposite said one side, spaced arms extending from the side of said body having said wedge faces, and a base connecting the ends of the arms opposite the body.

5. In a draft gear for railroad cars, a plunger including a wedge body having a bufiing surface on one side and having opposite outwardly directed wedge faces on the side opposite said one side, spaced arms extended from the side having said wedge faces, and a base connecting the ends of the arms opposite the body, said base having a central opening.

References Cited in the file of this patent UNITED STATES PATENTS 

